This invention is directed to phosphorus and sulfur derived oelfinic adducts as multifunctional lubricant additives or multifunctional fluids or partial replacement fluids.
The use of metallic phosphorodithioate derivatives, such as zinc dithiophosphate, has been well-known for their multifunctional antioxidant/antiwear/anticorrosion properties in a variety of lubricant applications, especially in engine oils.
The use of ashless phosphorodithioate derivatives, such as alkylmercapto-alkyl,-O,O-dialkyldithiophosphates (U.S. Pat. No. 2,759,010), phosphorodithioate easter (U.S. Pat. No. 3,544,465, 3,350,348 and 3,644,206), reaction products of sulfurized olefin adducts of phosphorodithioic acids (U.S. Pat. No. 4,212,753), and addition products of dihydrocarbyl thiophosphoric acids to conjugated dienes (U.S. Pat. No. 3,574,795), have found widespread lubricant application as multifunctional anticorrosion, antiwear, and antioxidant additives, as well as agriculture applications as herbicides and pesticides.
Lubricants, such as lubricating oils and greases, are subject to oxidative deterioration at elevated temperatures or upon prolonged exposure to the elements, heat, light, oxidants, or catalysts. Such deterioration is evidenced, in many instances, by an increase in acidity and in viscosity, and when the deterioration is severe enough, it can cause metal parts to corrode. Additionally, severe oxidation leads to a loss of lubrication properties, and in especially severe cases this may cause complete breakdown of the device being lubricated. Many additives have been tried, however, many of them are only marginally effective except at high concentrations. Improved antioxidants are clearly needed.
Antioxidants or oxidation inhibitors are used to minimize the effects of oil deterioration that occur when, for example, hot oil is contacted with air. The degree and rate of oxidation will depend on temperature, air and oil flow rates and, of particular importance, on the presence of metals that may catalytically promote oxidation. Anitoxidants generally function by prevention of chain peroxide reaction and/or metal catalyst deactivation. They prevent the formation of acid sludges, darkening of the oil and increases in viscosity due to the formation of polymeric materials.
Water (moisture) is another critical problem. In spite of even extraordinary precautionary efforst water is found as a film or in minute droplets in vessels containing various hydrocarbon distillates. This brings about ideal conditions for corrosion and damage of metal surfaces of the vessels and the materials contained therein. Also in the lubrication of internal combustion engines, for example, quantities of water are often present as a separate phase within the lubricating system. Another serious problem in respect to metallic surfaces in contact with adjacent metallic surfaces is the surface wear caused by the contact of such surfaces. One material capable of effectively coping with such problems as these simultaneously, is highly desireous.
It has now been found that the use of addition adducts of dithiophosphoric acid to internal olefins, functionalized olefins and alpha-olefins provides good high and low temperature lubricating properties with exceptional antioxidant and antiwear/EP activity with potential corrosion inhibiting, friction reducing, and high temperature stabilizing properties. These phenomena are equally advantageous when these compositions are used at less than 100% or a 0-10% additive concentrations, or 10-90% partial fluid replacement levels.
Accordingly, it is an objective of this invention to provide lubricant compositions of improved multifunctional capability having anitoxidant/high temperature stabilizing properties, antiwear/EP activity with corrison inhibiting and friction reducing characeristics. It is a further objective to provide novel additive products derived from the aforementioned addition adducts of dithiophosphoric acid to various olefinic materials and to provide novel lubricant compositions containing the hereinabove/below described additive products in amounts of up to about 100%.